Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems, (e.g., a Long Term Evolution (LTE) system, or a New Radio (NR) system). A wireless multiple-access communications system may include a number of base stations or access network nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE).
Certain wireless communication systems may use one or more analog transmission waveforms and/or reception waveforms. For example, transmitting devices, such as a UE and/or a base station, may include one or more transmit chains that each generate an analog waveform for transmission. A receive chain of the transmitting device, however, may experience difficulty with concurrent or simultaneous receive operations due to interference or distortion introduced by a transmission, such as from the transmit chain(s). For example, non-linear and/or linear behavior of the analog radio frequency (RF) component(s) of the transmit chain (e.g., power amplifier, switches, antenna tuners, etc.) may generate undesired energy in other portions of the spectrum. This undesired energy may be considered interference when received at the receive chain(s). In some aspects, this effect may be considered transmitter self-jamming. For the case of a single transmit carrier, the distortion may manifest as harmonics of the fundamental operating frequency. In an example where uplink carrier aggregation (UL-CA) techniques are used, the distortion may manifest as inter-modulation distortion (IMD) where a combination of two transmit frequencies may fall at the receive frequency. The resultant co-channel interference can significantly de-sensitize the receiver.
As downlink received signal strength indicator (RSSI) of a received signal increases, conventional techniques for canceling interference from the received signal become less efficient and/or may actually introduce noise to the received signal. There is hence a need to provide improved mitigation of interference caused by a transmitter.